Health monitoring: a pathway to improved sustainable drainage system maintenance

Sustainable drainage systems (SuDSs) have gained popularity, however, guidance for monitoring and maintaining SuDS components remains limited, especially considering their long-term performance in changing environmental conditions. This study begins to address this gap by developing a proof-of-concept model for monitoring infiltration trench (IT) ‘health’. In this study, ‘health’ refers to the physical condition, performance, and overall well-being of the IT. A physical model, constructed following UK SuDS manual guidelines, serves as a testing ground to evaluate IT performance under various maintenance scenarios. The physical model was instrumented to deliver a system for health evaluation. By identifying distinct maintenance parameters, we assess the IT health in terms of infiltration and attenuation/storage volume. The two parameters of ‘leaf build-up’ (surface condition) and ‘sediment build-up’ (subsurface condition) were used as indicative health parameters. The IT instrumentation was able to quantify the adverse effect of sediment build-up on both storage volume and infiltration time. After the sediment was added, the average peak attenuation volume decreased by 40% under a low flow rate and by 20% under a high flow rate. Additionally, the average infiltration time dropped by 26% for both high and low flow rates. Results suggest soil moisture measurements can indicate when IT maintenance is needed.